Suturing instruments for assisting a medical practitioner in placing stitches during surgical procedures are useful, particularly in surgical procedures requiring the placement of secure and accurate sutures in difficult to access regions of the body, including internal body regions. Instruments and methods for suturing remotely are especially important in minimally invasive surgical procedures such as laparoscopic and endoscopic procedures. In addition to helping to access remote regions of the body requiring suturing, suturing instruments may also allow the efficient manipulation of very small needles and the formation of small and precise sutures
Arthroscopic rotator cuff repair is one example of a technically challenging procedure that requires the placement of sutures in difficult to reach regions, as well requiring precise placement of sutures. The procedure may be performed with the patient under general anesthesia, and small (e.g., 5 mm) incisions may be created in the back, side, and front of the shoulder, and an arthroscope and instruments may be switched between each of these positions as necessary. The rotator cuff tear may be visualized, and the size and pattern of the tear is assessed. Thin or fragmented portions are removed and the area where the tendon will be reattached to the bone is lightly debrided to encourage new blood vessel ingrowth for healing. Sutures may be placed to close a tear. Depending on the size and location of the tear, multiple suture stitches may be required. In many situations, an arthroscopic stitch passer and grasper are used to pass a suture through the tendon. A stitch passer and grabber are typically only capable of making a single stitch, and must be withdrawn and reloaded in order to make multiple stitches. Similarly, a separate arthroscopic knot tying instrument is typically used to pass and tie knots in the suture to secure the repair. Furthermore, most currently available suturing instruments are limited in their ability to be maneuvered, particularly over thicker tissue regions, and may require additional space so that additional surgical instruments, including forceps or other graspers.
For example, the ArthroSew™ is a commercially available bi-directional suturing device with multiple-pass capability that has two jaws hinged to open V-like (from a common pivot). A suture is attached to the center of a double-ended needle and can be passed between the two jaws. At least one end of the needle protrudes from one or the other jaw at all times. The protruding needle may become caught in tissue, a problem that is exacerbated in difficult to access regions and regions offering limited maneuverability, such as the subacromial space of the shoulder. In addition, it is not possible to pass a stitch through thick (>4 or 5 mm) tissue because if the needle is too long then the device cannot be inserted through a cannula and is not easily manipulated around or off of tissue when sewing. When attempts are made to pass a stitch through such thick tissues, the needle commonly is released free within the shoulder because it is not captured within the far jaw (the needle does not make it all the way through the tissue). Additionally, the ArthroSew™ and similar devices require the user to flip a toggle switch in the handle each time the user desires to alternate the needle between the jaws while sewing. This step has been shown to be difficult for surgeons to master. Similar devices are described in U.S. Pat. Nos. 5,814,054, 5,645,552, 5,389,103, 5,645,552, and 5,571,090. Other suture passers (including continuous suture passers) include rotating suture passers, in which a curved suture needle is driven about an axis through successive revolutions to pass through an adjacent tissue, forming a spiral stitch through the tissue. U.S. Pat. No. 5,540,705 to Meade et al., describes one such embodiment.
Meniscus repair is another example of a technically challenging procedure that requires the placement of sutures in difficult to reach regions. The meniscus is a C-shaped piece of fibrocartilage which is located at the peripheral aspect of the joint (e.g., the knee) between the condyles of the femur and the tibia on the lateral and medial sides of the knee. The central ⅔rds of the meniscus has a limited blood supply while the peripheral ⅓rd typically has an excellent blood supply. Acute traumatic events commonly cause meniscus tears in younger patients while degenerative tears are common in older patients as the menisci become increasingly brittle with age. Typically, when the meniscus is damaged, a torn piece may move in an abnormal fashion inside the joint, which may lead to pain and loss of function of the joint. Early arthritis can also occur due to these tears as abnormal mechanical movement of torn meniscal tissue and the loss of the shock absorbing properties of the meniscus lead to destruction of the surrounding articular cartilage. Occasionally, it is possible to repair a torn meniscus. While this may be done arthroscopically, surgical repair using a suture has proven difficult because of the hard-to-reach nature of the region and the difficulty in placing sutures in a way that compresses and secures the torn surfaces.
Arthroscopy typically involves inserting a fiberoptic telescope that is about the size of a pencil into the joint through an incision that is approximately ⅛ inch long. Fluid may then be inserted into the joint to distend the joint and to allow for the visualization of the structures within that joint. Then, using miniature instruments which may be as small as 1/10 of an inch, the structures are examined and the surgery is performed.
A typical meniscus has a flattened (“bottom”) and a concave top, and the outer cross-sectional shape is somewhat triangular. The outer edge of the meniscus transitions into the capsule. There are circumferential fibers extending along the curved length of the meniscus, as well as radial fibers, and more randomly distributed mesh network fibers. Because of the relative orientations and structures of these fibers, and the predominance of circumferential fibers, it may be beneficial to repair the meniscus by suturing radially (vertically) rather than longitudinally or horizontally, depending on the type of repair being performed.
Most prior art devices for suturing or repairing the meniscus are only capable of reliably repairing vertical/longitudinal tears. Such devices are not typically recommended for repair of radial tears, particularly not arthroscopically/minimally invasively. Further, the prior art devices typically place horizontal mattress suture patterns rather than vertical mattress suture patterns because vertical patterns are considerably more difficult (if not impossible) for surgeons to place when using these devices. Vertical mattress patterns would have improved pull through strength because of the aforementioned predominance of circumferential collagen fibers found within the meniscus structure. See, e.g., Boenisch, U. W., et al, “Pull-out strength and stiffness of meniscal repair using absorbable arrows or Ti-Cron vertical and horizontal loop sutures,” Am J Sports Med. 1999 September-October; 27(5):626-31. Additionally; prior art devices are only capable of point fixation; that is they cannot compress the tears uniformly across the torn surface. Finally, such prior art devices are designed for repairing peripheral vertical meniscus tears (torn from the superior surface to the inferior surface in line with the C-shape of the meniscus) and are incapable of repairing commonly encountered radial meniscus tears.
There is a need for methods and device capable of repairing tissue particularly tissue that is difficult to access, in particular, it would be useful to provide methods and device for repair of tissue in which the suture or stitch may be formed completely from within the tissue (e.g., in a closed, minimally invasive, or percutaneous procedure), including loading and unloading of the suture passing element. The methods and system described herein may address some of these needs. Also described herein are systems and devices, including anchors and anchoring systems, which may be used to repair tissue.